namespace Zcbot.WindowsNode;

internal sealed class ConfigurationForm : Form
{
    private readonly TextBox server = CreateTextBox("http://127.0.0.1:8765");
    private readonly TextBox nodeName = CreateTextBox(Environment.MachineName.ToLowerInvariant());
    private readonly TextBox enrollmentCode = CreateTextBox(usePassword: true);
    private readonly Button register = CreateButton("注册并连接", primary: true);
    private readonly Button resetIdentity = CreateButton("清除本机身份并重新注册");
    private readonly CheckBox startAtLogin = new()
    {
        Text = "登录 Windows 后自动启动节点",
        AutoSize = false,
        Height = 32,
        Dock = DockStyle.Top,
    };
    private readonly Label state = new()
    {
        AutoSize = true,
        Font = new Font("Microsoft YaHei UI", 12, FontStyle.Bold),
    };
    private readonly Label detail = new() { AutoSize = true, Dock = DockStyle.Fill, ForeColor = Color.FromArgb(71, 85, 105) };
    private readonly Label identity = new() { AutoSize = true, Dock = DockStyle.Fill, ForeColor = Color.FromArgb(71, 85, 105) };
    private bool changingStartup;

    internal event Func<EnrollOptions, Task>? RegisterRequested;
    internal event Action? ResetIdentityRequested;

    internal ConfigurationForm()
    {
        Text = "zcbot Windows Node";
        AutoScaleMode = AutoScaleMode.Dpi;
        ClientSize = new Size(760, 690);
        MinimumSize = new Size(720, 640);
        StartPosition = FormStartPosition.CenterScreen;
        Font = new Font("Microsoft YaHei UI", 9);
        FormBorderStyle = FormBorderStyle.Sizable;
        BackColor = Color.FromArgb(245, 247, 250);

        var page = new TableLayoutPanel
        {
            Dock = DockStyle.Fill,
            Padding = new Padding(28, 24, 28, 24),
            AutoScroll = true,
            ColumnCount = 1,
            RowCount = 7,
            BackColor = BackColor,
        };
        page.ColumnStyles.Add(new ColumnStyle(SizeType.Percent, 100));
        Controls.Add(page);

        var heading = new TableLayoutPanel
        {
            AutoSize = true,
            Dock = DockStyle.Top,
            ColumnCount = 1,
            Margin = new Padding(4, 0, 4, 18),
        };
        heading.Controls.Add(new Label
        {
            Text = "zcbot Windows Node",
            AutoSize = true,
            Font = new Font("Microsoft YaHei UI", 20, FontStyle.Bold),
            ForeColor = Color.FromArgb(15, 23, 42),
        });
        heading.Controls.Add(CreateHint("连接本机科研软件与 zcbot 的受控执行节点"));
        page.Controls.Add(heading);

        var statusCard = CreateCard(148);
        statusCard.Controls.Add(CreateSectionTitle("节点状态"));
        statusCard.Controls.Add(state);
        statusCard.Controls.Add(detail);
        statusCard.Controls.Add(identity);
        page.Controls.Add(statusCard);

        var configCard = CreateCard(360);
        configCard.Controls.Add(CreateSectionTitle("注册配置"));
        configCard.Controls.Add(CreateHint(
            "首次连接需要管理员在 zcbot 管理端生成注册码。注册码默认 10 分钟有效，成功注册一次后立即失效。"));
        AddField(configCard, "zcbot 服务地址", server, "本机测试通常使用 http://127.0.0.1:8765");
        AddField(configCard, "节点名称", nodeName, "用于管理员识别这台 Windows 计算节点");
        AddField(configCard, "一次性注册码", enrollmentCode, "格式类似 ZCN-…；它不是日常登录密码，也不会被长期保存");
        var actions = new FlowLayoutPanel
        {
            AutoSize = true,
            FlowDirection = FlowDirection.LeftToRight,
            WrapContents = false,
            Dock = DockStyle.Fill,
            Margin = new Padding(0, 12, 0, 0),
        };
        actions.Controls.Add(register);
        actions.Controls.Add(resetIdentity);
        configCard.Controls.Add(actions);
        page.Controls.Add(configCard);

        var runtimeCard = CreateCard(104);
        runtimeCard.Controls.Add(CreateSectionTitle("运行设置"));
        runtimeCard.Controls.Add(startAtLogin);
        runtimeCard.Controls.Add(CreateHint("关闭配置窗口后，节点仍会在系统托盘运行。右键托盘图标可重连或退出。"));
        page.Controls.Add(runtimeCard);

        var securityNote = CreateHint("安全说明：Node Token 由 Windows DPAPI 加密保存，不在界面中显示，也不会写入日志。");
        securityNote.Margin = new Padding(4, 14, 4, 0);
        page.Controls.Add(securityNote);

        register.Click += async (_, _) => await RegisterAsync();
        resetIdentity.Click += (_, _) => ResetIdentity();
        startAtLogin.CheckedChanged += (_, _) => ToggleStartup();
        FormClosing += (_, eventArgs) =>
        {
            if (eventArgs.CloseReason == CloseReason.UserClosing)
            {
                eventArgs.Cancel = true;
                Hide();
            }
        };
        startAtLogin.Checked = StartupRegistration.IsEnabled;
        ApplyStatus(NodeStatus.Create(NodeState.NotRegistered, "尚未注册"), null);
    }

    internal void ApplyStatus(NodeStatus status, NodeConfig? config)
    {
        state.Text = status.State switch
        {
            NodeState.Online => "● 在线",
            NodeState.Connecting => "● 正在连接",
            NodeState.NotRegistered => "● 尚未注册",
            NodeState.AuthenticationRequired => "● 需要重新注册",
            NodeState.Offline => "● 离线",
            _ => "● 已停止",
        };
        state.ForeColor = status.State switch
        {
            NodeState.Online => Color.ForestGreen,
            NodeState.Connecting => Color.DarkOrange,
            NodeState.NotRegistered or NodeState.AuthenticationRequired => Color.Firebrick,
            _ => Color.DimGray,
        };
        detail.Text = $"{status.Message}　{status.ChangedAt:HH:mm:ss}";
        identity.Text = config is null
            ? $"配置文件：{NodePaths.ForCurrentMachine().ConfigPath}"
            : $"节点：{config.NodeName}\nNode ID：{config.NodeId}\n服务：{config.ServerUrl}";
        server.Enabled = config is null;
        nodeName.Enabled = config is null;
        enrollmentCode.Enabled = config is null;
        register.Enabled = config is null && status.State != NodeState.Connecting;
        resetIdentity.Visible = config is not null;
        if (config is not null)
        {
            server.Text = config.ServerUrl.AbsoluteUri.TrimEnd('/');
            nodeName.Text = config.NodeName;
            enrollmentCode.Clear();
        }
    }

    private void ResetIdentity()
    {
        var answer = MessageBox.Show(
            "这会删除本机加密身份，随后需要使用新注册码重新注册。请同时让管理员禁用云端旧节点。是否继续？",
            "清除本机节点身份", MessageBoxButtons.YesNo, MessageBoxIcon.Warning,
            MessageBoxDefaultButton.Button2);
        if (answer == DialogResult.Yes)
        {
            ResetIdentityRequested?.Invoke();
        }
    }

    private async Task RegisterAsync()
    {
        if (RegisterRequested is null)
        {
            return;
        }
        try
        {
            register.Enabled = false;
            detail.Text = "正在注册…";
            var options = EnrollOptions.Parse([
                "--server", server.Text, "--name", nodeName.Text, "--code", enrollmentCode.Text]);
            await RegisterRequested(options);
        }
        catch (Exception exception) when (exception is NodeConfigurationException or HttpRequestException)
        {
            MessageBox.Show(exception.Message, "注册失败", MessageBoxButtons.OK, MessageBoxIcon.Error);
            register.Enabled = true;
        }
    }

    private void ToggleStartup()
    {
        if (changingStartup)
        {
            return;
        }
        try
        {
            StartupRegistration.SetEnabled(startAtLogin.Checked);
        }
        catch (Exception exception) when (exception is UnauthorizedAccessException or IOException)
        {
            MessageBox.Show(exception.Message, "自动启动设置失败", MessageBoxButtons.OK, MessageBoxIcon.Error);
            changingStartup = true;
            try
            {
                startAtLogin.Checked = StartupRegistration.IsEnabled;
            }
            finally
            {
                changingStartup = false;
            }
        }
    }

    private static TableLayoutPanel CreateCard(int minimumHeight)
    {
        var card = new TableLayoutPanel
        {
            AutoSize = true,
            AutoSizeMode = AutoSizeMode.GrowAndShrink,
            MinimumSize = new Size(0, minimumHeight),
            Dock = DockStyle.Top,
            ColumnCount = 1,
            Padding = new Padding(22, 18, 22, 18),
            Margin = new Padding(0, 0, 0, 14),
            BackColor = Color.White,
        };
        card.ColumnStyles.Add(new ColumnStyle(SizeType.Percent, 100));
        return card;
    }

    private static Label CreateSectionTitle(string text) => new()
    {
        Text = text,
        AutoSize = true,
        Font = new Font("Microsoft YaHei UI", 11, FontStyle.Bold),
        ForeColor = Color.FromArgb(30, 41, 59),
        Margin = new Padding(0, 0, 0, 8),
    };

    private static Label CreateHint(string text) => new()
    {
        Text = text,
        AutoSize = true,
        Dock = DockStyle.Fill,
        ForeColor = Color.FromArgb(100, 116, 139),
        Margin = new Padding(0, 2, 0, 4),
    };

    private static TextBox CreateTextBox(string text = "", bool usePassword = false) => new()
    {
        Text = text,
        UseSystemPasswordChar = usePassword,
        AutoSize = false,
        Height = 36,
        BorderStyle = BorderStyle.FixedSingle,
        Font = new Font("Segoe UI", 10),
    };

    private static Button CreateButton(string text, bool primary = false)
    {
        var button = new Button
        {
            Text = text,
            AutoSize = false,
            Size = new Size(primary ? 128 : 220, 38),
            FlatStyle = FlatStyle.Flat,
            BackColor = primary ? Color.FromArgb(37, 99, 235) : Color.White,
            ForeColor = primary ? Color.White : Color.FromArgb(51, 65, 85),
            Margin = new Padding(0, 0, 10, 0),
        };
        button.FlatAppearance.BorderColor = primary
            ? Color.FromArgb(37, 99, 235)
            : Color.FromArgb(203, 213, 225);
        return button;
    }

    private static void AddField(
        TableLayoutPanel layout, string label, Control control, string hint)
    {
        layout.Controls.Add(new Label
        {
            Text = label,
            AutoSize = true,
            Font = new Font("Microsoft YaHei UI", 9, FontStyle.Bold),
            ForeColor = Color.FromArgb(51, 65, 85),
            Margin = new Padding(0, 9, 0, 4),
        });
        control.Dock = DockStyle.Top;
        control.Margin = new Padding(0, 0, 0, 2);
        layout.Controls.Add(control);
        layout.Controls.Add(CreateHint(hint));
    }
}